


And the Heart is a Beast

by stardropdream



Category: Voltron: Legendary Defender
Genre: Alternate Universe - Modern Setting, Anal Sex, Bottom Shiro (Voltron), Established Relationship, Face-Sitting, Knotting, M/M, Oral Sex, Rimming, Top Keith (Voltron), Werewolf Keith (Voltron), Werewolf Sex
Language: English
Status: Completed
Published: 2019-05-03
Updated: 2019-05-03
Packaged: 2020-02-16 17:56:48
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,992
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18696460
Author URL: https://archiveofourown.org/users/stardropdream/pseuds/stardropdream
Summary: They’ve long since learned the best way to keep Keith himself during the moon, how best to keep the wolf calm despite their cramped city apartment. Long since learned what the wolf needs, what Keith needs. There’s a reason why Shiro proudly putconflict resolutionon his résumé, after all.Keith’s trust is a gift, Shiro thinks. Keith didn’t have to trust him with this secret, but he did. And years ago, when they first started dating, Shiro never would have imagined himself here, like this. But he can’t regret any of that— any of the moments he’s had with Keith or the profound trust he puts in his hands during each full moon.Or: Sex keeps Keith calm during the full moon.





	And the Heart is a Beast

**Author's Note:**

  * For [springofviolets](https://archiveofourown.org/users/springofviolets/gifts).



> Fic request from [Juna](https://twitter.com/springofviolets), who asked for some werewolf Keith knotting his boyf. Listen, we all know why we're here. 
> 
> Thank you to [Renée](https://twitter.com/bootyshortskeef) for reading this over for me!
> 
> Note on the tags: this fic does feature Shiro and Keith initiating sex before his transformation into a werewolf and they finish shortly before Keith's transformation finishes. Just be mindful of that if more wolf-y biology/behavior is going to squick you out! If you need more info before reading, just let me know. ♥ 
> 
> (Edited December 2019 for typos/grammar.)

“Huh,” Shiro says. 

It’s said more to himself, but he feels Keith look over from the couch where he’s sprawled out, legs stretched over the couch's arm. He has his arm slung over his eyes, blocking out the light.

“What?” Keith asks. 

Shiro doesn’t look away from the bay window, where he’s sitting in the last dredges of sunlight, watching some squirrels out on the sidewalk below. With deep gravity, he says, “Squirrels fuck.” 

An expansive silence follows this statement. Shiro glances away from the squirrels in time to see Keith lift his arm and give Shiro a vaguely stunned look. 

“Shiro… what the fuck?” Keith asks, although his mouth hints a bewildered smile, tone amused. 

Shiro gestures towards the window and the squirrels outside. “I was just looking at them and like… Every squirrel I’ve ever seen is the result of two other squirrels having sex.” 

Keith snorts, using his foot to scratch at his other foot. “Whatever you say, furry.” 

“You’re one to talk,” Shiro says affectionately as Keith huffs a laugh. 

“No, it’s still definitely you,” Keith teases. 

Shiro laughs again and shrugs. He can’t really deny it, and he’s hardly going to take it as an insult when it comes to Keith. Shiro hops off the cushion at the bay window and stalks over to Keith, flopping down at the end of the couch. He picks up and drops Keith’s feet into his lap. 

“How are you feeling?” he asks, running his hand over one ankle. 

“Itchy,” Keith confesses with only a small note of misery. Years ago, he’d likely have denied even that much.

Shiro nods. “Makes sense. Moonrise is soon.” 

“Yeah,” Keith mutters, staring up at the ceiling. He grunts as he pops his jaw when it starts to ache. 

Keith hasn’t started to transform yet, but Shiro’s gotten used to the subtle changes in Keith’s face as the full moon approaches. Keith can’t grow facial hair to save his life, except the few days leading up to the moon, and his jaw hints shadow. His eyes are darker, too, his smile just on the edge of feral, his canines suggesting fangs. 

Shiro runs his hand over Keith’s foot and ankle and up, scritching his nails through his fuzzy leg hair. This close to the moon, it feels more like fur, thick and coarse. 

“Hey,” Keith says, throaty, “Come here.”

And as if Shiro’s ever been one to ignore Keith in any circumstance, much less when he sounds like _that_. Shiro hums thoughtfully and shifts up, setting Keith’s feet down. He crawls over the length of the couch and approaches Keith, caging him in with arms and legs.

Keith watches him approach, eyes sharp in the dimming light. He tips his face up as Shiro approaches to meet Shiro as he ducks down. They kiss gently. It’s a soft kiss, slow and unhurried, and Shiro can’t help the little shiver at the feeling of Keith’s teeth dragging over his bottom lip, the hint of fangs as he sucks Shiro’s tongue into his mouth and cradles his jaw with a strong hand. 

Shiro hums quietly, pressing closer, letting Keith’s fingertips skate over his jaw. Keith’s kiss, his tongue and teeth, always leaves Shiro breathless. 

“Still thinking about squirrel sex?” Keith asks once they part, mouth quirked into a teasing smile. 

“Shut up,” Shiro laughs affectionately. He kisses him again just to swallow Keith’s little laugh. 

“I’m not hearing a no,” Keith mumbles against his mouth and then barks a little laugh when Shiro bites down hard on his bottom lip. 

It’s a nice sound to hear— rare enough leading up to the full moon that Shiro wants to protect it, wants to make sure Keith always feels happy. That’s the key, really. It’s always been his priority. He’ll take all the stupid squirrel jokes if it means Keith’s laughing. 

Somehow that thought alone is enough to make his heart thump hard in his chest. 

“Hey,” Shiro whispers once they part, pressing his forehead to Keith’s. 

“Mmm?” Keith hums, petting his fingers along Shiro’s jaw. His expression gentles when Shiro smooths his thumb over the swell of his bottom lip, thumbing at where he nipped him.

“I’ll take care of you,” Shiro murmurs. 

Keith gives a little sigh, nose brushing against Shiro’s. He presses a light kiss to Shiro’s thumb before Shiro can draw it back, simple but worshipful. There’s no tease in his voice when he answers, “I know. You always do.”

Keith tends to get agitated on the days leading up to the full moon, and it’s not like Shiro can blame him for it, either. But Keith is docile now, a forced calm he’s adopted after several months of practicing meditation with Shiro. And he trusts Shiro. The first time Keith ever admitted as much to Shiro, voice unsure, as if Shiro would snatch that away from him, Shiro knew he’d always be devoted to Keith in turn. If Keith places his trust in Shiro, then Shiro will do anything in his power to make it worth it for Keith.

He pets his fingers through Keith’s hair and cradles his cheek, pressing a few kisses to his jaw and working his way down the column of his neck. He nuzzles at the spot between neck and shoulder, pressing his mouth and tongue there, licking in slow, pointed laps. 

Keith laughs above him. “You know it doesn’t work when a human does it, right?” 

Shiro hums and doesn’t stop. He might not be able to scent Keith, but he knows it’s the act of staying close that calms Keith more than any supernatural werewolf ability could. Sure enough, he feels Keith hum and relax, going boneless. The more Shiro lingers, the looser Keith feels beneath him. 

The moon’s not set to rise for a little while yet but as the sun sinks to the horizon, Shiro pulls himself away to draw the curtains and lock the door with their second, heavier bolt. When he returns to the couch, Keith’s thrown the familiar pillows and blankets onto the floor, a makeshift, haphazard nest (as is Keith’s way). As Shiro approaches, Keith’s already halfway through tugging his shirt off. 

Shiro strides to him, stilling Keith’s movements and running his hands up his side. Keith sucks in a deep breath and sinks into the touch, seeking Shiro’s mouth. The kiss is slow again, gentle and patient, and Shiro tugs Keith’s shirt up and over his head for him, undoes his belt, and strips him down so he’s naked and trembling in his arms. 

“If I hurt you—” Keith starts, as he always does.

“Shh,” Shiro assures him, pressing a kiss to the corner of his mouth and then ducking down to kiss his throat. “We know how this works. It’s going to be fine, baby.” 

Keith grumbles, not quite words but just the sentiment of it. Shiro kisses his pulse point. 

They’ve long since learned the best way to keep Keith himself during the moon, how best to keep the wolf calm despite their cramped city apartment. Long since learned what the wolf needs, what Keith needs. There’s a reason why Shiro proudly put _conflict resolution_ under skills on his résumé, after all. 

Keith’s trust is a gift, Shiro thinks. Keith didn’t have to trust him with this secret, but he did. And years ago, when they first started dating, Shiro never would have imagined himself here, like this. And he has never regretted any of it— any of the moments he’s had with Keith or the profound trust he puts in his hands during each full moon. 

Shiro presses Keith down against the pillows and blankets before straddling his hips. Keith takes a breath and sprawls back, his eyes tracing Shiro’s hands as he thumbs open the buttons of his shirt, taking his time and making a show of it. It’s a tease and they both know it, but Shiro still does it— he knows how impatient Keith can get, especially when the wolf’s incoming. 

True enough, Keith lets out an appreciative sound, a half-growl that lances down Shiro’s spine. 

“Go faster,” Keith groans. “Or I’m ripping those clothes off you.”

“Maybe that’s what I want,” Shiro teases and rocks his hips down to grind against Keith. Keith’s breath hitches. Through the soft fabric of his pants, Shiro feels Keith’s cock twitch. 

His own teasing aside, Shiro really can’t afford to keep replacing the shirts he goads Keith into ripping, so with only a small bit of regret, he shrugs out of his shirt, tossing it aside. Next full moon, he’ll remember to wear a raggedy old shirt he’s planning on donating, maybe, just to have the satisfaction of Keith’s claws at his back, ripping his clothes right off him. 

Undressing takes a little maneuvering, since Keith’s possessiveness means he clamps his hands tight to Shiro’s hips and refuses to let him climb out of his lap. He has to shimmy from one leg to another to manage to get his jeans off. 

Keith’s fingers tease at the waistband of his boxer briefs, curling a little, as if debating ripping them off. But, again, Shiro can’t really afford to keep buying the silky underthings he likes. Underwear is expensive, even if he buys the semi-cheap brands. He coaxes Keith’s hands off his hips so he can thread their fingers together, pinning Keith’s hands over his head and pressing them chest to chest.

Keith growls, “You’re teasing me.” 

“Me? Never,” Shiro says with a warm smile as he leans in, taking his time to kiss Keith, licking into his mouth and sucking on his bottom lip just to hear Keith whimper. Shiro wriggles his hips back, shameless in grinding down on Keith’s cock. It’s one of his favorite parts, feeling the way Keith’s cock twitches and grows against his body. That he’s the one to make Keith feel this way.

“Teasing,” Keith murmurs, hands flexing in Shiro’s. He’s more than strong enough to shove Shiro off, to get his hands free, especially now with the wolf’s strength lingering underneath, but Shiro knows that’s part of what Keith loves— the promise of it, without threat, the feeling of Shiro pressing down against him. If they didn’t have to worry about Keith’s changing limbs tonight, he’d ride Keith for hours. 

Keith breaks the kiss with a soft breath, his face involuntarily turning towards the window. The curtains are drawn, but Shiro knows that beyond it, the moon’s rising. It’ll call to Keith now. Keith won’t be full wolf until it reaches its apex, but still Shiro watches the way the light starts to glow in Keith’s eyes, the slow flaring of his nostrils as he takes in a sharp breath.

Keith once tried to describe the draw to Shiro. Said it was like the way they always found one another in a wide room, their eyes locking. Shiro never thought he’d be in competition with the moon, but he’s always liked the poetry of it. 

“Hey,” Shiro whispers, cupping Keith’s cheek and guiding him back to meet his eyes. “Here with me.” 

“Shiro,” Keith whispers, eyes on him. He strains a little to get to him, lifting up and kissing him. 

Shiro hums, encouraging, and kisses him back, lets Keith growl low in his throat and bite at Shiro’s lip just to make him gasp, just so he can sweep his tongue into his mouth. Keith is still himself, Shiro can tell, nothing animalistic stinging the kiss just yet. Keith’s always so careful at the beginning of the night. 

They kiss, taking their time with it. Shiro knows how kissing can focus Keith, how simple and luxurious it feels to just press their bodies together, to feel the swelling of Keith’s cock against his hip as he pets his hand up and down his chest, brushes his fingers over Keith’s throat. Keith lays worship to his mouth, as he does in all things, devotional and almost spiritual in the way he presses their mouths together, the way he whispers Shiro's name between the hush of their breath, the drag of their teeth. 

Shiro could happily kiss Keith for hours and he knows how important it is now, how much it centers Keith, how much Keith needs to be treated gently. It takes Keith’s mind off the transformation, the fits and starts of it, the growing pains of changing ligaments and animalistic desire. 

They don’t know what it is about sex that keeps Keith’s mind focused. It’s something primal, perhaps. Shiro isn’t sure if it’s something for all werewolves or if it’s just Keith in particular, just Keith’s specific intensity when it comes to Shiro— all focus, all love, all worshipful possessiveness directed solely at Shiro. Maybe sex helps all werewolves. Maybe sex helps Keith. Maybe it’s just sex with Shiro that helps Keith. 

Or maybe, Shiro thinks as he takes Keith’s cock in hand and gives a tentative pull, feeling Keith’s gasp against his mouth, it’s none of those things and all those things at once. Keith once joked it was because Shiro looks so good taking his cock and though Shiro turned pink at the time, sometimes he wonders if maybe that’s it. Keith’s never put the word _mate_ on the table, really, but it’s been heavily implied and certainly Shiro wouldn’t shy away from it if Keith were to call him such. They haven’t actually talked about it. 

He might have caught Keith looking at rings a few weeks back, but they haven’t talked about that either. 

Shiro breaks the kiss to press his mouth to Keith’s neck. He strokes Keith’s cock in slow, languid pulls that make Keith’s breath hitch into little whines. Shiro kisses down his chest, mouthing at his skin, spelling his love for him out over the lines of his muscles. He traces the trail of hair leading down to his cock with his tongue just to hear Keith laugh, breathless and cock twitching in Shiro’s strong hand. 

Shiro smiles up at Keith as he curls his mouth around him, suckling at the cockhead just to hear Keith whimper. Keith does, a low whine that builds in his throat as he rocks his hips up. Shiro hums happily and holds his cock to his mouth, his other hand reaching down blindly to tug off his underwear so he’s naked with Keith. 

Keith whines and drapes a leg over Shiro’s shoulder, the prickling feeling of growing fur dragging over his skin. Shiro pulls away from Keith’s cock just to press a sloppy kiss to his inner thigh instead. 

He hears Keith growl and, a moment later, feels Keith press against him, overpowering him as he flips them over. Now Shiro’s the one sprawled on his back, Keith straddling his shoulders. His fingers, pricked with the ghost of claws, cradle his head to keep him from bumping it against the hardwood floor. 

Shiro peers up at Keith, mouth open in quiet surprise before he laughs. “Well,” he teases, running his hands over Keith’s thighs, grinning. “You could have just said if you wanted to sit on my face so badly.” 

Keith growls at him again. He’s not fully non-verbal yet, Shiro knows, and it’s more for the effect of it— Keith knows how much Shiro loves the sound of his growl. Keith’s fingers tug on his hair, teasing, nails dragging against his scalp. 

“Gonna do it,” Keith rumbles, Shiro’s only warning. Shiro loves that part, when the line between man and wolf starts blurring. Keith’s voice has always been deep and gravely— something Shiro’s always loved, long before he knew his secret, long before Keith trusted him with that— but the growling edge to it from the wolf always makes Shiro tremble. 

Shiro opens his mouth to him and lets Keith angle himself, fingers dragging through his bangs and using them to yank his head back, to open his throat, and slips his cock into his mouth. He fucks into him, his other hand gripping the couch for leverage, holding himself steady. 

Shiro groans, gripping Keith’s thighs hard and guiding him in, coaxing Keith to go deeper. Outside, the moon continues to rise but Keith’s changes come slow. Shiro feels the bulge and shift of his muscles, the curve of his cock. He squeezes the backs of Keith's thighs and drags his hands up, cupping his ass and pulling him down close so he chokes on his cock. 

But Keith backs off a little when Shiro chokes and Shiro lets out his own whine, digging his fingers tight into Keith’s ass and pulling him down against him, laving his tongue along his cock to coax him to fuck him harder, deeper. He flutters his eyes shut and arches his body beneath Keith, greedy for it. He could do this for hours, too, if Keith let him.

He knows he could let Keith come like this. It’d be easy— just let Keith go mindless, a little frenzied, let him fuck his throat raw. It’d be enough to satisfy the wolf and would help keep Keith in his mind. 

But it isn’t what Shiro wants. He taps against Keith's ass to catch his attention. Keith stills immediately. 

When Shiro opens his eyes and looks up at him, Keith looks moon-touched— his eyes dark and heated, his jaw just a little elongated, panting. His chest heaves, flushed in the dying light of their apartment. But he’s still, legs trembling a little with the effort. 

“Baby,” Shiro whispers, soothing, running his hands up Keith’s back and along his ribs. “Look at you.” 

Keith shakes his head, face flushed, his hair falling heavy over his shoulders, framing his handsome face. He looks half-wild but still himself, his grip murderously tight on the couch and in Shiro’s hair. 

“Baby,” Shiro coos again, turning his head to press a sloppy kiss to Keith’s cock, where it rests against his cheek. “You know I want you in me.” 

“Shiro- _oo_ ,” Keith whimpers, the tail-end of his name like a dog’s low whine. 

“I know you want it,” Shiro whispers, can hear the wolf’s desire and Keith’s desire, twisted together, can hear the whimpering longing in Keith’s breath as he pants, rocking his hips forward. Shiro takes the tip of Keith’s cock in his mouth, suckling gently, but teasing. He lets go and shifts his head back before Keith can keep thrusting forward. 

Keith shifts back with some effort, his body bowing as he moves. He moves down the length of Shiro’s body, head ducked down. He presses his forehead to Shiro’s chest and shudders a little as a new wave of his transformation washes over him. It doesn’t hurt Keith, at least not when he’s distracted like this, but it takes his focus away the only way a shifting body can. 

Holding Keith like this, Shiro’s arms tight around him as he feels the transformation ripple through him, how Keith changes in a slow tide rather than a crashing wave, Shiro finds he can only be grateful that Keith will trust him with this. 

Shiro brushes his fingers through Keith’s hair, petting him. He feels Keith’s ears change shape beneath his fingertips, feels the flex and movement of Keith’s jaw as he works it loose. His back bows, his hands more claw than nails. 

When it passes, Keith lifts his head to look up at Shiro. Shiro whispers his name, cupping his flexing jaw with his hands, his thumbs brushing over his cheeks. Keith smiles at him, to assure him, and his teeth are harder-edged, pointed and feral. 

“Shiro,” Keith whispers, worshipful, his voice threaded with his desire. The wolf shines in his expression— love and possession, a desire to keep Shiro close, to make Shiro his. 

“Go on,” Shiro coaxes. “Take what you want, Keith.” 

Shiro had prepared himself earlier in the day for this, but still he fishes the lube out from between the couch cushions. He’d prefer for Keith to finger him open, has always loved the way Keith feels inside him, how ferocious he becomes in his desire to get Shiro off, always finding Shiro’s prostate with brutal and unrelenting determination. But Keith’s far enough in his transformation now that his claws dig hard into the pillows beneath him and while Shiro loves that thrill of danger, he also knows Keith would never forgive himself if he accidentally hurt Shiro.

Shiro shifts against the blankets, their makeshift nest, and spreads his legs as Keith scoots down over him, snuffling against his skin, inhaling deep. The first time they ever slept together, long before Shiro knew about Keith’s secret, he’d whispered hot and dark into Shiro’s ear that he was the best thing he’d ever smelled. At the time, Shiro’d been too far gone to think about the statement too much, but in hindsight, and now, seeing Keith lap at Shiro’s stomach, Shiro knows it for the compliment it is. 

Keith ducks down between Shiro’s thighs, fangs scraping over his inner thigh. Shiro gives a surprised, pleased shout, legs falling open and body trembling. Keith snuffles against his skin, pupils blown wide and yellow bleeding out from behind his irises. Shiro sighs at the sting of his fangs, the scrape of his claws as he cups Shiro’s thighs and lifts his legs up to drape over his shoulders. He wriggles closer with a needy whine. 

Keith licks at Shiro’s thighs, to the crease of leg to pelvis, laps at his balls and then the base of his cock with a pathetic, pleased whimper. Shiro’s hand falls between them, twisting up in Keith’s hair and guiding him forward. 

Keith seeks where Shiro presses two fingers inside himself with a perfunctory twisting preparation. He’s still loose from fingering himself open earlier in the day, but he knows Keith will appreciate the extra care, both for the visual and for the reassurance of Shiro’s readiness. Keith groans and laps at Shiro’s rim, tongue dragging over Shiro’s knuckles and then along the pinked edge. Shiro gasps, pleased. 

“Yeah, Keith,” he whispers, fingers twisted tight in his hair, pulling Keith in. “Baby. Please.” 

Fueled on by the reaction, Keith’s instincts guide him forward. His tongue is larger now, thick and long, lapping at him with determined focus. Shiro pets through his hair just to drag out Keith’s keens and whimpers, nearly drowned out by the pleased gasps each swipe of Keith’s tongue punches out of Shiro’s throat. 

Keith is merciless, dragging his tongue over his sensitive skin, pressing inward when Shiro tugs his fingers out to make space for him. His tongue fills Shiro, twisting and lapping at his rim, tugging him open. Shiro cries out Keith’s name, knowing the wolf inside Keith will appreciate the louder display, the way his body falls open and pliant for him. 

Keith's tongue fucks into him and his claws prick at Shiro’s thighs as he holds him up and open, casual in his display of strength, and Shiro’s crying out. His hand lets go of Keith’s hair to fist around his cock and give it a few pathetic tugs.

But Keith snarls, ripping away from Shiro’s hole, eyes wide and feral when he growls, “No.” 

Shiro’s gasping, chest heaving, but he lets go of his cock immediately and cups Keith’s chin, thumb pressing to Keith’s lip. Keith opens his mouth and nips at his thumb, sharp enough to sting.

“I need you,” Shiro pants. “Come here.” 

Keith growls, looking satisfied. When he lifts, Shiro can see the fur flushing down his body, moving more towards wolf than human now. 

“Go on, Keith,” Shiro whispers. “Do what you want.” 

That works— it always does— and he watches Keith rock over him, a deep growl punctuating his movement as he crawls over him. He bites down hard at Shiro’s throat, never hard enough to break skin and risk turning Shiro, but a wet, heated pressure against his skin as Keith situates himself above him. 

Keith ruts against him, his cock big and wet against Shiro’s thighs, the vee of his hips, the flat of his stomach. It catches and drags against Shiro’s cock and Shiro moans Keith’s name loudly, body arching. 

Shiro reaches down blindly, fisting Keith’s cock and guiding him as Keith tries to situate, trying to balance himself on changing limbs.

“Shiro,” Keith moans against his throat and Shiro kisses the top of his head. Keith is all tense muscles, cock sliding through Shiro’s hand in deep thrusts as he guides Keith down to press against his hole. He’s all corded tendons and strong body, his fur and hair soft against him, his words panting, pleading syllables. 

Keith licks at Shiro’s throat, whining, as he feels the tip of his cock press to Shiro’s hole. 

“Keith, sweetheart,” Shiro says, feeling Keith still in his arms, waiting for Shiro’s command. “I’m yours. _Make_ me yours.”

Keith snarls against his throat. It’s animal instinct that pushes him forward, rocking his hips in a smooth, slow slide that leaves Shiro crying out at the breach of it. Even if he’s prepared, it still spreads him open, wide and throbbing. 

It still takes Shiro’s breath away: all that raw, feral power condensed into such a small body, the power while Keith holds Shiro down. He’s never hurt Shiro, even in those early months when Keith revealed himself and they didn’t know how to control the wolf. Even then, clawing at the ground and growling, he never once attacked Shiro. Even the wolf knows, Shiro thinks. Even the wolf knows that Shiro is his. 

Shiro’s always been used to his strength, used to being large and, to some, intimidating. He loves that power in Keith, how easily he holds Shiro down, pins him to his makeshift nest. Shiro loves to feel small, in these moments, knowing that Keith is taking care of him. Knowing that, for all of Keith’s supernatural strength and power, he fucks Shiro like he’s precious, something to cherish, like he is fragile and worthy of gentleness.

“Love you,” he whispers in Keith’s changing ear, the fine point, the furred edge as he adjusts to the girth of Keith’s swelling cock, as he rocks his body forward to meet each deep thrust. “Love you so much. You’re so good for me.”

Keith whines, a low, thrumming sound that’s all animal and buries his face against Shiro’s throat, panting. 

“Yeah,” Shiro murmurs. “Yeah, Keith. Give it to me. I want your knot.” 

The knot is, truthfully, Shiro’s favorite part. He gasps out, body arching, as he feels himself split— feels how big Keith is, how full Keith can make him. 

Keith fucks into him, steady and firm. Shiro rocks against the floor and, not for the first time, is grateful for the pillows and blankets cushioning his body against the driving, animal thrusts. He grunts, his body burning from desire, body held and split open by Keith, who towers over him. 

He curls his legs tight around Keith’s pulsing hips, drags his hands down hard over Keith’s back, the powerful muscles shifting as he grinds against Shiro. His black fur is so soft, warm under his hands, his body poised and powerful. The teeth at his throat are razor sharp now, but so gentle against his skin. He can imagine, if he were to reach down, that he’d find Keith’s tail. He loves pulling it, using it to guide Keith’s pace as he thrusts into Shiro. 

He loves sex with Keith. He loves when they go slow, taking hours to take each other apart, curled around each other. But he loves this, too, these moments when Keith can’t control his desire, when he fucks into Shiro with an almost frenzied need, always leaving Shiro crying out for more. 

“Mine,” Keith growls, so graveled out that it barely sounds like Keith anymore. 

Shiro shudders. “Yeah. Yeah—” 

“Mine,” Keith says again, lower. “My mate.” 

Shiro’s eyes fly open as he cries out, his cock giving a pathetic twitch between their bodies, his body sloppy and slick. The gasp that rattles out of him is wet and startled and then, with a deep breath, his grip tightens on Keith. He’s nodding. 

“Yeah, baby.” He bites at Keith’s ear, whimpering. “I’m yours.” 

Keith growls, satisfied and rumbling. Shiro can feel it rattling in his chest where they’re pressed, flushed together. He shifts, squirming beneath Keith’s hulking body, and tries to wrap his hand around his cock again. 

With a snarl that tapers into a hiss, Keith snatches his hands and slams them down above his head, his eyes piercing when he pulls away from Shiro’s neck enough to stare at him. Shiro moans in surprise, cock throbbing, but he finds himself arching, legs flexing at Keith’s hips. 

“Fuck,” he sobs out. “ _Keith._ ” 

He feels Keith’s cock swelling inside him, his base thickening up. Shiro keens out softly, clutching at Keith as he feels the beginnings of that knot. 

He can hear himself begging for it, whispering it hot into Keith’s ear, rocking his body against that swelling cock. 

“Fuck me,” Shiro groans, “Give me that knot. Fill me, Keith. Make me yours.” 

Again, it works— his wolf is nothing if not predictable in his desires— and Keith rocks forward mercilessly, claws digging hard enough into the pillows beneath Shiro to rip them, little feathers fluffing up in the air. Shiro pants, goading him on anyway, body aching sweetly with the force of Keith’s thrusts. 

When he comes, Shiro feels the swell of the knot, the base of his cock expanding and stretching Shiro nearly to his limits. He shudders, letting Keith lick into his mouth. Keith lets out a low howl, something stunted in the city apartment they share, when out in the wild he’d let it run long and triumphant. 

The building pressure is enough to get Shiro to moan weakly, trapped beneath Keith and hard cock pressed against the soft down of Keith’s underbelly. Keith’s cock twitches and spills inside him, thick and warm, his body slicking up with Keith’s come. It fills him and fills him— and Shiro somehow always manages to forget just how much more Keith comes when he’s the wolf. 

“Keith, baby… Can I come?” he whimpers.

Keith huffs and shifts. He glares at his paw, as if only now realizing the fingers have morphed, the razor-sharp claws. He looks put-out by it, frowning. Shiro can’t help the little laugh, catching his paw and kissing the tendon. 

“You’ll get me next time,” Shiro promises. “Just watch me.”

Keith growls his permission and Shiro fists himself in his hand and strokes only three times before he comes with a low cry, eyes fluttering shut. He knows Keith’s watching him, triumphant and pleased to have made Shiro feel this good. 

Shiro slumps once his body stops trembling, feels the swell of come inside him from Keith’s knot, still plugging him. They won’t be able to pull away for a few minutes more, not until the knot goes down. 

Keith snuffles at Shiro’s neck, licking long stripes over his sweaty skin. Shiro luxuriates in the attention, petting his fingers sluggishly through Keith’s fur. 

“Love you,” he mumbles, for good measure, and knows that if Keith weren’t too far gone from verbal communication, he would say it back. Shiro accepts the gentle nip at his shoulder. 

Shiro can’t help the pained little whine when, finally, the knot deflates and Keith shifts out of him. If he could, he’d make Keith stay there, make him get hard inside him and fuck him again. But he knows the position isn’t right for Keith now. If he wants Keith’s knot again, he’ll have to put himself on hands and knees for Keith to mount him. 

He sighs out, pliant and flooded with warmth. He can feel Keith’s come leaking out of him, dribbling down his thighs and staining the blankets beneath him. He’s gotten used to doing strenuous amounts of laundry since being with Keith. At least he didn’t shred his underwear this time, he supposes. 

When Shiro opens his eyes again, Keith is there beside him. He’s full wolf now, his body morphed and changed. He’s massive, curling easily around Shiro’s body. 

Keith is himself— Shiro can see the human intelligence in his eyes, the recognition and knowledge that he’s here, in this moment, with Shiro.

Shiro cracks a smile and lifts his hand, petting his fingers through Keith’s soft fur, scratching at the spot just behind one of his ears. Keith’s eyes shut and he bows his head, snuffling against Shiro’s neck and giving him a few little licks, scenting him. 

“Yeah, Keith. Baby,” Shiro murmurs. “I’m good. You’re so good. You okay?”

Keith gives a little whine, the barest nod of his head, as he settles around Shiro, curling protectively around him. Shiro can’t help the little smile, closing his eyes and luxuriating in Keith’s doting attention. 

“Give me a little bit and we can go again if you want,” Shiro says, only because now Keith can’t actually call him a furry to his face, although he knows he’s thinking it very loudly. It’ll probably be the first thing he says after moonset.

Keith licks at his chest, his scratchy tongue dragging over one of Shiro’s nipples and giving a pleased rumble when Shiro gasps. He moves further down, his touch much gentler as he laps at Shiro’s skin, cleaning him. Shiro pets his fingers through his fur, tracing down over his back and tugging playfully on his tail just to get Keith to groan. 

“Think the neighbors are going to leave a passive aggressive note on our door again about keeping it down?” Shiro asks with a grin. Keith huffs. Keith hates the passive aggressive neighbors not for their note-leaving but for their spoiled labradoodle that Keith insists has an _attitude._

Shiro lets Keith clean him up. Once he pauses, Shiro reaches down and cups Keith’s jaw, guiding him away when he makes to lick the come out of him. 

“Leave it,” he murmurs. “Want to feel you.”

Keith relents, returning to his side and curling around him. He licks at his neck and shoulder instead. 

“So,” Shiro murmurs, fingers tangling in the soft fur at Keith’s nape. He turns his head to look at Keith, meeting his eyes. “I’m your mate, huh?” 

Keith ducks his head a little, the wolf equivalent of embarrassment as his eyes flicker away. Shiro lets out a soft little sound, soothing him with his fingers, brushing through his fur and tracing the ridges of his spine. 

Shiro smiles when Keith’s eyes glance back up to him. “I… I was kind of already thinking of us as that, for what it’s worth.” 

He likes to think he’s gotten pretty good at reading Keith’s expressions when he’s the wolf, and he thinks this time Keith must look surprised, then relieved. He shuffles closer to Shiro and plops his head down heavy on his chest, looking up at him with literal puppy dog eyes. 

Keith makes a soft sound and Shiro smiles, brushing his fingers through his fur and scritching at his ears. 

Years ago, Shiro never would have guessed that this is where his life would take him— never, in a million years, would have guessed the love of his life would be a werewolf. But then, really, he wouldn’t have it any other way. He can’t imagine his life without Keith. 

“Keith,” he whispers, “my mate.” 

Keith’s tail thumps against the floor and he lets out a soft little breath that ghosts over Shiro’s chest. Shiro grins and then laughs when Keith scrambles up and starts lapping at his face like an overeager puppy, relief and happiness radiating off him. 

Shiro laughs, sputtering when Keith just won’t stop. But he can hardly mind. He’ll say it again, too, as many times as he needs to— can’t wait to say it a second time when Keith can say it back.

**Author's Note:**

> This story is part of the [LLF Comment Project](https://longlivefeedback.tumblr.com/llfcommentproject) (including the [LLF Comment Builder](https://longlivefeedback.tumblr.com/commentbuilder)), which was created to improve communication between readers and authors. This author invites and appreciates responses, including:
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